Magic Celtic Triquetra Knot Amulet Black Agate Stone Pendant Necklace Best Amulets Collection. Magic Celtic Triquetra Knot Amulet Black Agate Stone NecklaceMagic Celtic Triquetra Knot Amulet Black Agate Stone Pendant Necklace Necklace Size: Adjustable Cord, Shortest: 17 inches, Longest: 24 inches Natural Gemstones Comes with Branded Packaging